The long-term objective of this multinational collaboration is the development of a series of individual difference instruments that will measure personality/temperament structure in young children from two years to l2 years of age. These instruments will be based on the natural language descriptions of parents, teachers and children select countries, including but not limited to the U.S.A., Netherlands, Belgium, China and Greece. In each country, investigators are conducting identical research protocols that begin with the free description of children followed by the coding of these descriptors into a taxonomy based on Dutch and American personality research using adult free language descriptors. Frequency analyses of these descriptors will lead to items describing the most frequent and salient descriptors that will in each country using free sorting and informant-group feedback will detect the major categories of personality in each culture and be further analyzed by participant ratings of children in new samples in each country. Item and factor analyses will lead to instruments that are developmentally and cross-nationally coordinated via adult and child natural language description. In the final phase of the study, we will begin of a series of construct validity analyses, comparing these new instruments with extant measures of childhood individual differences. By adopting the lexical, natural language approach to the development of these instruments, we will simultaneously test the robustness of the structure of personality language across cultures and languages and also simplify the assessment of childhood individual differences where there are a multitude of constructs and hopefully align the assessment of children with the growing consensus in the adult personality literature that the domain of individual differences as measured by rating scales or questionnaire is almost completely described by five broad factors. If there can be an alignment of constructs in childhood and adult personality domains, we can begin to trace continuities and discontinuities within and across the same domains in childhood and adulthood. by linking the two domains via lexical analyses we may contribute to the unification of the study of personality development from childhood to adulthood.